Many important questions in psychology are concerned with understanding the complex interrelationships between our impressions of others and our expectations about the feeling, behaviors, and emotions of those others. We propose to do research that will contribute to our understanding of these questions by developing empirically based quantitative models of how psychological processes at the level of individuals affect and are affected by people's interpersonal relationships. In order to reduce the problem to a size that is manageable, but still rich and interesting in its complexities, we will begin by focusing our work on understanding judgments of dyadic interactions in which the participants are described simply by traits (e.g., friendly, cruel) or social identities (e.g., parent, athlete, host) and in which the behaviors of the participants are described by interpersonal verbs (e.g., helps, harms, takes advantage of). Thus, our initial focus is on understanding judgments about sequences of interpersonal events such as "The cruel man ridiculed the therapist. The therapist tried to help the cruel man. The cruel man sneered at the therapist. The cruel man walked away from the therapist." In more standard English this sequence would be described something like, "In spite of being ridiculed by the cruel man, the therapist tried to help him. The man simply sneered at the therapist, and walked away." Someday we hope to be able to realistically model actual interactions between people, and in the present project we plan to work on simulating some rudimentary aspects of interaction sequences that occur between psychotherapists and patients. Ultimately, we hope our theory, and its realization as a computer program, will help us design better methods of prevention and better treatments for the broad range of mental disorders that are critically affected by people's reaction to their interpersonal relationships.